The first solar-powered steam generation system in Canada to be integrated with an existing natural gas power plant is in the early stages of construction in Medicine Hat, Alberta.
“The city already has a combined cycle power plant, which uses natural gas to drive a steam powered turbine,” said Russ Smith, manager of sustainability with the city.
“These are big troughs that focus the sun’s energy into a transfer fluid that boils water and creates steam, which is fed into the system with existing steam.”
The main objective of the commercial-scale Medicine Hat Concentrating Solar Thermal Energy Demonstration Project is to assess the potential of using this particular solar technology throughout Alberta.
The $9 million project involves the manufacture and installation of parabolic dishes to focus sunlight onto a black rod, which will in turn heat up fluid that goes into a steam turbine. The next step is to find a contractor to construct the troughs.
“Now that we have firmed up the funding, we are moving into the detailed design phase,” said Smith. “There are a handful of manufacturers in the world that do this work. We have some people in New Mexico meeting with suppliers and engineers, but we have not selected a specific supplier.”
While this technology has been successful in California and Spain, Medicine Hat would be the first Canadian city with electricity powered by solar thermal energy.
The estimated project cost breakdown is: equipment and infrastructure ($3.5 million), installation manpower and engineering ($4 million), power plant integration ($500,000), as well as technical monitoring and project management ($1 million).
“Our goal is to use local trades as much as possible,” said Smith. “The majority of the labour doing the installation will be local, as long as the right people are managing and doing the technical oversight for the project.”
The project is expected to create 12.8 man years of employment, with about 11.8 man years coming from local sources. The remaining man year will be for the provision of international technical expertise.
The detailed design work for the project will be done in late 2010 and early 2011. Site construction work is expected to begin in September 2011, with mechanical completion in June 2012.
Commercial operation is scheduled for August 2012 and the final outcome of the demonstration project will be known by November 2013.
The projected annual operational and maintenance costs for the installed solar thermal energy system are anticipated to be $40,000 per year.
Despite the fact that the City of Medicine Hat is located near huge reserves of natural gas, the city is exploring options for alternative sources of energy.
The city, in partnership with Natural Resources Canada, commissioned a study in 2007 to determine the technical feasibility of integrating solar thermal parabolic trough collectors into the city’s current electric generation infrastructure.
The report indicated that the required area for a one megawatt solar field is less than 10,000 m2. Based on the available solar radiation at the Medicine Hat site, the annual solar electric energy production was estimated at 1,390 MWh on top of the current electricity production.
The solar energy facility will have a solar-to-electricity efficiency of 11 per cent, which is a value similar to solar plants in California. The project has a commitment of $3 million from the city, and the remaining $6 million will be provided by the federal and provincial governments.
RICHARD GILBERT, www.journalofcommerce.com